Abstract: A switch which is activated by a voice signal which is higher than the normal voice signal but which is sustained by the normal voice signal and which is disabled by the absence of any voice signal much below the normal voice signal for a predetermined period of time. The voice actuated switch is particularly useful inside a high noise environment, such as the mask of a scuba diver or aviator in which the breathing noise is of the same order of magnitude as ordinary speech noise. The voice activated switch includes a HI comparator which provides an activation signal only when a word is spoken above a certain HI loudness level, and a LO comparator which provides a sustaining level when exposed to a signal from noise or voice at a normal level for a selected time interval.